KR20100103370A - Display uint - Google Patents

Abstract

PURPOSE: A display unit is provided to improve the purity of color and reduce the spectrum width of extracted light by a multiple interference of light generated from a light emitting layer. CONSTITUTION: Organic electroluminescent elements and a pixel circuit are formed in pixels(11R, 11G, 11B). The pixel circuit is composed of sustain capacitances which are connected between a first transistor(T_WS), a second transistor(T_Dr), and the gate and the source of the second transistor. The first transistor records an image signal. Based on the recorded image signal, the second transistor drives the organic electroluminescent elements. Gate lines(WSL) are connected with the gate of the first transistor through contacts.

Description

Display unit {DISPLAY UINT}

The present invention relates to a display unit including an organic EL (electroluminescence) element.

In recent years, in the field of a display unit for performing image display, as a light emitting element of a pixel, a display unit using a current-driven optical element, for example, an organic EL element, whose light emission luminance changes in accordance with a flowing current value, has been developed, and commercialization proceeds. (For example, see Japanese Patent Laid-Open No. 2008-083272).

An organic EL element is a self-luminous element, unlike a liquid crystal element. Therefore, in the display unit (organic EL display unit) using the organic EL element, since no light source (backlight) is required, the visibility of the image is higher, the power consumption is lower, and the power consumption is lower than that of the liquid crystal display unit requiring the light source. The response speed of the device is fast.

In the organic EL display unit, similarly to the liquid crystal display unit, there are a simple (passive) matrix method and an active matrix system as its driving methods. Although the former has a simple structure, there is a problem that it is difficult to realize a large and high-precision display unit. Therefore, development of the active matrix system is prosperous at present. In this system, the current flowing through the light emitting elements arranged for each pixel is controlled by an active element (typically a thin film transistor (TFT)) provided in a driving circuit provided for each light emitting element.

15 shows a general configuration of a general organic EL display unit. The display unit 100 illustrated in FIG. 15 includes a display unit 110 in which a plurality of pixels 120 are arranged in a matrix, and a driver (horizontal drive circuit 130 and a write scan circuit) for driving each pixel 120. 140 and a power supply scanning circuit 150 are provided.

Each pixel 120 is comprised of the pixel 120R for red, the pixel 120G for green, and the pixel 120B for blue. The pixels 120R, 120G, and 120B are composed of an organic EL element 121 (organic EL elements 121R, 121G, 121B) and a pixel circuit 122 connected thereto as shown in Figs. 16 and 17. have. 16 illustrates a circuit configuration of the pixels 120R, 120G, and 120B. 17 shows the layout of the pixels 120R, 120G, and 120B.

The pixel circuit 122 is composed of a sampling transistor T _WS , a holding capacitor C _s , and a driving transistor T _Dr , and has a circuit structure of 2Tr1C. The gate line WSL drawn out from the write scan circuit 140 is extended in the row direction, and is connected to the gate 123A of the transistor T _WS through the contact 126A. The drain line DSL drawn out from the power supply scanning circuit 150 is also extended in the row direction and is connected to the drain 124C of the transistor T _Dr via the lead wiring 128A. The signal line DTL drawn out from the horizontal drive circuit 130 is extended in the column direction, and is connected to the drain 123C of the transistor T _WS through the contact 126B and the lead wire 128B. have. The source 123B of the transistor T _WS is connected to the gate 124A of the driving transistor T _Dr and one end (terminal 125A) of the holding capacitor C _s through the contact 126C. have. The source 124B of the transistor T _Dr and the other end (terminal 125B) of the storage capacitor C _s are connected to the anode 127A of the organic EL element 121 via the contact 126D. The cathode 127B of the organic EL element 121 is connected to the external cathode line CTL.

18 shows an example of a cross-sectional configuration along the line A-A of FIG. The pixels 120R, 120G, and 120B have a gate insulating film 112, an insulating protective film 113, and an insulating planarization film 114 on the substrate 111 at a portion corresponding to the A-A line in FIG. 17. A gate 124A (terminal 125A) and a gate 123A are formed between the substrate 111 and the gate insulating film 112.

Between the gate insulating film 112 and the insulating protective film 113, and directly above the gate 124A, the channel 131, the sources 132 and 124B, the drains 133 and 124C, and the protective film 134 are provided. Formed. The channel 131 is formed in direct contact with the gate 124A of the gate insulating layer 112. In addition, between the gate insulating film 112 and the insulating protective film 113, and directly above the gate 123A, the channel 135, the drains 136 and 123C, the sources 137 and 123B, and the protective film 138. ) Is formed.

The organic EL element 121 is formed on the insulating planarization film 114. The organic EL element 121 has a structure in which, for example, the anode 127A, the organic layer 127C, and the cathode 127B are sequentially stacked on the substrate 111 side. In the same plane as the anode 127A, a cathode auxiliary wiring 117 is provided between the anode 127A and a predetermined gap therebetween, and an opening (between the anode 127A and the cathode auxiliary wiring 117) is provided. 117A) exists.

For example, as shown in FIG. 18, the organic EL element 121 has a structure in which the anode 127A, the organic layer 127C, and the cathode 127B are stacked in order on the substrate 111 side. The anode 127A has a function as a reflective layer, and the cathode 127B has a function as a semi-transmissive reflective layer. These anodes 127A and cathode 127B constitute a resonator structure for resonating light generated in a light emitting layer (not shown) included in the organic layer 127C. That is, the surface of the organic layer 127C side of the anode 127A and the surface of the organic layer 127C side of the cathode 127B constitute a pair of reflecting mirrors, and the light generated in the light emitting layer is generated by the pair of reflecting mirrors. It resonates and is taken out at the cathode 127B side. As a result, the light generated in the light emitting layer causes multiple interference, and the resonator structure acts as a kind of narrow-band filter, whereby the half value width of the spectrum of the extracted light is reduced and color purity is improved.

An opening defining insulating film 115 is formed in the same plane as the anode 127A of the organic EL element 121, and an insulating protective film 116 is formed on the organic EL element 121. The opening defining insulating film 115 has an opening (EL opening 115A) corresponding to the anode 127A. The EL opening 115A is formed in a part of the region facing the upper surface of the anode 127A, and the opening defining insulating film 115 covers the outer edge (peripheral) of the anode 127A. That is, only a part of the top surface of the anode 127A is exposed on the bottom surface of the EL opening 115A, and the organic layer 127B is exposed on the bottom surface of the EL opening 115A of the top surface of the anode 127A. We are in contact with part that we do.

The cathode auxiliary wiring 117 surrounding the anode 127A is formed around the anode 127A within the same plane as the anode 127A. The cathode auxiliary wiring 117 is provided to uniformize the in-plane potential distribution of the cathode 127B, and is electrically connected to the cathode 127B. The cathode auxiliary wiring 117 is disposed with the anode 127A and a predetermined gap therebetween, and an opening 117A is present between the anode 127A. Therefore, the cathode auxiliary wiring 117 maintains insulation with respect to the anode 127A.

Here, as shown in FIG. 18, light L of some of the light generated in the light emitting layer is not output from the cathode 127B side, and starts leaking to adjacent pixels. When the light L which starts to leak enters the channel 131 of the transistors T _Dr and T _{WS in} adjacent pixels, the light leakage current increases, which causes malfunction of the pixel circuit 122. .

In particular, when blue light having a short wavelength enters the channel 131, the TFT characteristics change, such as the minimum physical quantity voltage Vth, which causes the gate reaction to shift with time, and the long-term reliability of the TFT is deteriorated. There is a problem. When the channel 131 contains amorphous silicon (a-Si) or microcrystalline Si (μ-Si), the deterioration of the long-term reliability of the TFT becomes remarkable.

For example, as shown in FIG. 19, a pixel 120B included in one pixel 120 includes a pixel 120G included in the pixel 120 and another pixel 120 adjacent to the pixel 120. Is disposed between the pixels 120R included in. In this case, blue light L leaking from the organic layer 127C of the pixel 120B is incident on the transistor T _{Dr in the} pixel 120G and the transistor T _{WS in the} pixel 120R, and the transistor There is a problem that the long-term reliability of (T _Dr , T _WS ) is deteriorated.

This invention is made | formed in view of the said problem, and the objective is to provide the display unit which can reduce the fall of transistor long-term reliability.

The display unit of the present invention includes a plurality of organic EL elements having different emission colors and a display unit having a plurality of pixel circuits each provided with one pixel for each organic EL element. The pixel circuit has a first transistor for recording for recording a video signal, a second transistor for driving for driving an organic EL element based on a video signal recorded by the first transistor, and a storage capacitor. have. Among the first transistors and the second transistors, the third transistor provided in correspondence with the second organic EL element adjacent to the first organic EL element is the first holding capacitor provided in correspondence with the second organic EL element. In comparison with this, it is disposed away from the first organic EL element.

In the display unit of the present invention, the third transistor provided in correspondence with the second organic EL element adjacent to the first organic EL element is compared with the first holding capacitor provided in correspondence with the second organic EL element, It is arrange | positioned away from the 1st organic electroluminescent element. Therefore, compared with the case where the distance A to a 1st organic electroluminescent element of a 3rd transistor is closer than the distance B to a 1st organic electroluminescent element of a 1st storage capacitance, it is 1st. The amount of light leaking from the organic layer in the organic EL element into the third transistor is small.

According to the display unit of the present invention, the incident amount of light leaking from the organic layer in the first organic EL element into the third transistor is compared with the case where the distance A is closer than the distance B. Less. Thereby, when the 1st organic electroluminescent element has the organic layer which produces the light which can deteriorate a 1st transistor and a 2nd transistor, the fall of the long-term reliability of a 3rd transistor can be reduced. .

Other objects, features and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings.

1 is a schematic diagram of a display unit according to an embodiment of the present invention.
2 is a circuit diagram of the pixel of FIG.
3 is a layout diagram of pixels of red color in FIG. 1;
4 is a layout diagram of pixels for blue and green in FIG. 1;
5 is a layout diagram of pixels of FIG. 1;
FIG. 6 is a cross-sectional view along line AA of the pixel of FIG. 3; FIG.
7 is a cross-sectional view along the line BB of the pixel of FIG. 3;
8 is a characteristic diagram showing the VI characteristic of the pixel of FIG.
Fig. 9 is a plan view showing a rough configuration of a module including display units of the above embodiments.
10 is a perspective view showing an appearance of an application example 1 of a display unit according to the embodiment;
Fig. 11A is a perspective view showing the appearance as seen from the outside of Application Example 2, and B is a perspective view showing the appearance as seen from the back side.
12 is a perspective view showing the appearance of Application Example 3. FIG.
Fig. 13 is a perspective view showing the appearance of Application Example 4.
14A is a front view of an application example 5 in an open state, B is a side view thereof, C is a front view thereof in a closed state, D is a left side view, E is a right side view, F is a top view, and (G) is a bottom view.
15 is a schematic view of a conventional display unit.
16 is a circuit diagram of a pixel of FIG. 15.
17 is a layout diagram of pixels of FIG. 15;
18 is a cross-sectional view along the AA line of the pixel of FIG. 17;
19 is a layout diagram of pixels of FIG. 15;

EMBODIMENT OF THE INVENTION Hereinafter, the best form for implementing this invention is demonstrated in detail with reference to drawings. The description will be made in the following order.

1. About configuration

2. Layout

3. Sectional Composition

4. Motion and Effects

5. Modifications

6. Modules and Application Examples

Rough composition

1 shows an example of the entire configuration of a display unit 1 according to an embodiment of the present invention. The display unit 1 is formed around the display unit 10 and the periphery of the display unit 10 on, for example, a substrate 40 (to be described later) made of glass, silicon (Si) wafer, resin, or the like. The circuit part 20 (drive part) is provided.

The display unit 10 arranges the plurality of pixels 11 in a matrix form over the entire surface of the display unit 10, and displays an image based on the externally input video signal 20a by active matrix driving. will be. Each pixel 11 includes a pixel 11R for red, a pixel 11G for green, and a pixel 11B for blue.

2 shows an example of a circuit configuration of the pixels 11R, 11G, and 11B. In the pixels 11R, 11G and 11B, the organic EL elements 12 (12R, 12G and 12B) and the pixel circuit 13 are provided as shown in FIG. In addition, the organic EL element 12B of this embodiment is corresponded to the specific example of the "1st organic electroluminescent element" of this invention, and the organic EL element 12R and 12G of this embodiment are the " It corresponds to the specific example of "2nd organic electroluminescent element."

The pixel circuit 13 is composed of a holding capacitor C _s connected between the transistor T _WS , the transistor T _Dr , and the gate-source of the transistor T _Dr , and has a circuit configuration of 2Tr1C. The transistor T _WS is a recording transistor for recording a video signal. The transistor T _Dr is a driving transistor for driving the organic EL element 12 based on the video signal recorded by the transistor T _WS . The transistors T _WS and T _{Dr are} formed of, for example, an n-channel MOS thin film transistor (TFT (Thin Film Transistor)).

In addition, the transistor T _WS of the present embodiment corresponds to a specific example of the "first transistor" of the present invention, and the transistor T _Dr of the present embodiment corresponds to the "second transistor" of the present invention. It corresponds to a concrete example. In the present embodiment, the transistors T _WS and T _Dr included in the pixels 11R and 11G correspond to specific examples of the "third transistor" of the present invention. It is a transistor provided corresponding to the adjacent organic EL elements 12R and 12G. In the present embodiment, the storage capacitors C _s included in the pixels 11R and 11G correspond to specific examples of the "first holding capacitor" of the present invention, and the organic EL elements 12R and 12G are represented. It is installed holding capacity correspondingly.

The peripheral circuit section 20 includes a timing control circuit 21, a horizontal drive circuit 22, a write scan circuit 23, and a power supply scan circuit 24. The timing control circuit 21 includes a display signal generating circuit 21A and a display signal holding control circuit 21B. In the peripheral circuit portion 20, a gate line WSL, a drain line DSL, a signal line DTL, and a ground line GND are provided. In addition, the ground line is connected to ground and becomes a ground voltage (reference voltage) when connected to ground.

The display signal generation circuit 21A displays the display signal 21a for displaying on the display unit 10 for each screen (for each display of one field), for example, based on the externally input video signal 20a. To generate.

The display signal holding control circuit 21B configures the display signal 21a output from the display signal generating circuit 21A for each screen (for each display of one field), for example, from a static random access memory (SRAM) or the like. It is stored in the field memory. The display signal holding control circuit 21B also serves to control the horizontal drive circuit 22, the write scan circuit 23, and the power source scan circuit 24 to drive each pixel 11 to operate in conjunction with each other. . Specifically, the display signal holding control circuit 21B receives the control signal 21b for the write scanning circuit 23, the control signal 21c for the power supply scanning circuit 24, and the display signal driving circuit 21C. Are output to the control signal 21d, respectively.

The horizontal drive circuit 22 can output a voltage corresponding to the control signal 21d output from the display signal holding control circuit 21B. Specifically, the horizontal drive circuit 22 applies a predetermined voltage to the pixel 11 selected by the write scan circuit 23 via the signal line DTL connected to each pixel 11 of the display unit 10. It is to supply.

The write scanning circuit 23 can output the voltage corresponding to the control signal 21b output from the display signal holding control circuit 21B. Specifically, the write scanning circuit 23 supplies a predetermined voltage to the pixel 11 to be driven through the gate line WSL connected to each pixel 11 of the display unit 10, and for sampling. To control the transistor T _WS .

The power supply scanning circuit 24 can output a voltage corresponding to the control signal 21c output from the display signal holding control circuit 21B. Specifically, the power supply scanning circuit 24 supplies a predetermined voltage to the pixel 11 to be driven through the drain line DSL connected to each pixel 11 of the display unit 10, thereby providing an organic EL. Light emission and quenching of the element 12R and the like are controlled.

layout

Next, the connection relationship and arrangement | positioning of each component are demonstrated with reference to FIGS. 3 shows an example of the layout of the pixel 11R, and FIG. 4 shows an example of the layout of the pixels 11G and 11B. 5 shows an example of the layout of the pixel 11. 5, the pixels 11G and 11B contained in one pixel 11 and the pixel 11R included in the other pixel 11 adjacent to the pixel 11 are shown.

First, the common matters of the pixels 11R, 11G, and 11B will be described. The gate line WSL drawn out from the write scan circuit 23 is extended in the row direction and is connected to the gate 31A of the transistor T _WS through the contact 34A. The drain line DSL drawn out from the power source scanning circuit 24 is also extended in the row direction and is connected to the drain 32C of the transistor T _Dr via the lead wire 36A. The signal line DTL drawn out from the horizontal drive circuit 22 is formed to extend in the column direction, and is connected to the drain 31C of the transistor T _WS through the contact 34B and the lead wire 36B. have. The source 31B of the transistor T _WS is connected to the gate 32A of the driving transistor T _Dr and one end (terminal 33A) of the holding capacitor C _s . The source 32B of the transistor T _Dr and the other end (terminal 33B) of the storage capacitor C _s are connected to the anode 35A of the organic EL element 12 via the contact 34D. . The cathode 35B of the organic EL element 12 is connected to the cathode line CTL.

Next, different points between the pixels 11R, 11G, and 11B will be mainly described. The pixels 11R, 11G, and 11B are arranged in order in the row direction within one pixel 11. That is, the pixel 11G is disposed on the right side (right side in the row direction) of the pixel 11R, the pixel 11B is disposed on the right side of the pixel 11G, and the other pixel (on the right side of the pixel 11B). The pixel 11R of 11 is arrange | positioned.

For example, as illustrated in FIGS. 3 and 5, the pixel 11R is a layout in which the layout of the pixel 11B is reversed left and right. The transistors T _Dr and T _WS in the pixel 11R are disposed away from the organic EL element 11B in the adjacent pixel 11B as compared with the storage capacitor C _{s in the} pixel 11R. That is, the transistor (T _Dr, T _WS), the pixels (11R) the storage capacitor (C _s) of the pixels (11B) side of a straight line (L _R) extending in the same time the tangent in the column direction at an end of the inside in the pixel (11R) In the relation with the organic EL element 11B, the organic EL element 11B in the adjacent pixel 11B is disposed on the opposite side. The transistors T _Dr and T _{WS in the} pixel 11R are different from the organic EL elements 11B in the adjacent pixel 11B in a relationship with the storage capacitor C _{s in the} pixel 11R as shown in FIG. 5. It is preferable to arrange on the opposite side. In other words, the transistors T _Dr and T _WS in the pixel 11R are preferably arranged in the pixel 11R at the region farthest from the organic EL element 11B in the adjacent pixel 11B.

For example, as illustrated in FIGS. 4 and 5, the pixel 11G is a layout in which the layout of the pixel 11R is reversed left and right. The transistors T _Dr and T _WS in the pixel 11G are disposed away from the organic EL element 11B in the adjacent pixel 11B as compared with the storage capacitor C _{s in the} pixel 11G. That is, the pixel transistor (T _Dr, T _WS), the storage capacitor (C _s) of pixels (11B) the straight line (L _G) at the same time the tangent extending in the column direction at the ends of the side of the in-pixel (11G) in (11G) In the relation with the organic EL element 11B, the organic EL element 11B in the adjacent pixel 11B is disposed on the opposite side. The transistors T _Dr and T _WS in the pixel 11G are arranged on the opposite side to the organic EL element 11B in the adjacent pixel 11B in relation to the holding capacitor C _{s in the} pixel 11G. desirable. That is, it is preferable that the transistors T _Dr and T _WS in the pixel 11G are disposed in the pixel 11G in the region farthest from the organic EL element 11B in the adjacent pixel 11B.

For example, the pixel 11B has the same layout as that of the pixel 11G, as shown in FIG. 5. The transistors T _Dr and T _WS in the pixel 11B are disposed close to the organic EL element 11G in the adjacent pixel 11G as compared with the storage capacitor C _{s in the} pixel 11B. In addition, the pixel 11B may have a layout different from that of the pixel 11G.

Sectional composition

FIG. 6 shows a cross-sectional configuration along the line AA of FIG. 3. 6 includes a cross section of the transistor T _WS . FIG. 7 shows a cross-sectional configuration along the line BB of FIG. 3. 7 includes a cross section of the transistor T _Dr. In addition, in this embodiment, what reversed the cross-sectional structure of FIG. 6 left-right corresponded to the cross-sectional structure along the AA line of FIG. 4, for example, and reversed the cross-sectional structure of FIG. For example, it corresponds to the cross-sectional structure along the BB line of FIG.

The pixels 11R, 11G, and 11B each have a gate insulating film 41, an insulating protective film 42, and an insulating planarization film 43 on the substrate 40 at portions corresponding to the AA and BB lines in FIG. 3. have. The gate insulating film 41 functions as a gate insulating film of the transistors T _WS and T _Dr. The insulating protective film 42 covers and protects the transistors T _WS and T _Dr. The insulating planarization film 43 is provided for the purpose of planarizing the base of the organic EL element 12, and covers the entire surface of the insulating protective film 42.

In the portion corresponding to the AA line in FIG. 3 (the portion including the cross section of the transistor T _WS ), a gate 31A and a terminal 33A are formed between the substrate 40 and the gate insulating film 41. On the other hand, in the part (part including the cross section of transistor T _Dr ) corresponding to AA line of FIG. 4, the gate 32A is formed between the board | substrate 40 and the gate insulating film 41. As shown in FIG. The gate 31A is generally formed around the region facing the EL opening 44A described later. The terminal 33A and the gate 32A are generally formed in an area facing the EL opening 44A. The gate insulating film 41 covers the entire surface including the substrate 40, the gates 31A and 32A, and the terminal 33A.

Between the gate insulating film 41 and the insulating protective film 42 and directly above the gate 31A, the channel 51, the sources 52 and 31B, the drains 53 and 31C, and the lead-out wiring 36B. And the protective film 54 is formed. The channel 51 is formed in direct contact with the gate 31A of the gate insulating film 41. The source 52 is formed in contact with one end of the channel 51, and a source 31B is formed in contact with the source 52 thereon. The drain 53 is formed in contact with the other end of the channel 51, and a drain 31C is formed in contact with the drain 53 thereon. The channel 51, the source 52, and the drain 53 include, for example, amorphous silicon (a-Si), microcrystalline Si (μ-Si), or low temperature polysilicon. The protective film 54 is formed between the sources 52 and 31B and the drains 53 and 31C, and covers the non-contact area with the source 52 and the drain 53 of the channel 51.

Between the gate insulating film 41 and the insulating protective film 42 and directly above the gate 32A, the channel 55, the sources 56 and 32B, the drains 57 and 32C and the protective film 58 are formed. It is. Further, a lead wire 36B is formed between the gate insulating film 41 and the insulating protective film 42 and next to the drain 32C. The channel 55 is formed in direct contact with the gate 32A of the gate insulating film 41. The source 56 is formed in contact with one end of the channel 55, and the source 32B is formed in contact with the source 56 thereon. The drain 57 is formed in contact with the other end of the channel 55, and a drain 32C is formed in contact with the drain 57 thereon. The channel 55, the source 56 and the drain 57 are composed of, for example, amorphous silicon (a-Si), microcrystalline Si (μ-Si) or low temperature polysilicon. The passivation film 58 is formed between the sources 56 and 32B and the drains 57 and 32C, and covers the non-contact area between the source 56 and the drain 57 of the channel 55.

The pixels 11R, 11G, and 11B have the organic EL element 12 on the insulating planarization film 43. The organic EL element 12 has a structure in which the anode 35A, the organic layer 35C, and the cathode 35B are stacked in order on the substrate 40 side, for example. The organic layer 35C is, for example, on the anode 35A side in order, a hole injection layer having a high hole injection efficiency, a hole transport layer having a high hole transport efficiency to the light emitting layer, and light emission by recombination of electrons and holes. The light emitting layer which generate | occur | produces the light emitting layer, and the electron carrying layer which improved the electron transport efficiency to a light emitting layer are included. The organic layer 35C of the pixel 11R contains a material that emits red light. The organic layer 35C of the pixel 11G contains a material that emits green light. The organic layer 35C of the pixel 11B contains a material that emits blue light. Blue light emitted from the organic layer 35C of the pixel 11B strongly has a property of degrading the transistors in the pixels 11R and 11G adjacent to the pixel 11B. In addition, the red light emitted from the organic layer 35C of the pixel 11R and the green light emitted from the organic layer 35C of the pixel 11G also slightly degrade the transistor in the pixel adjacent to the pixel 11R or 11G. But have.

The anode 35A has a function as a reflective layer, and the cathode 35B has a function as a semi-transmissive reflective layer. These anodes 35A and 35B constitute a resonator structure for resonating light generated in the light emitting layer 35C. That is, a pair of reflecting mirrors is formed by the surface on the organic layer 35C side of the anode 35A and the surface on the organic layer 35C side of the cathode 35B, and the light generated in the light emitting layer 35C is limited to this range. It resonates by a pair of reflecting mirrors, and is taken out from the cathode 35B side. As a result, the light generated in the light emitting layer 35C causes multiple interference, and the resonator structure acts as a kind of narrow-band filter, thereby reducing the half-value width of the spectrum of light to be extracted and improving color purity.

The pixels 11R, 11G, and 11B have an opening defining insulating film 44 in the same plane as the anode 35A of the organic EL element 12, and have an insulating protective film 45 on the organic EL element 12. .

The opening defining insulating film 44 has an opening (EL opening 44A) corresponding to the anode 35A. The EL opening 44A is formed in a part of the region facing the upper surface of the anode 35A, and the opening defining insulating film 44 covers the outer edge (periphery) of the anode 35A. That is, only a part of the top surface of the anode 35A is exposed on the bottom surface of the EL opening 44A, and the organic layer 35C is exposed on the bottom surface of the EL opening 44A among the top surfaces of the anode 35A. We are in contact with part that we do.

The insulating protective film 45 covers the whole surface of the cathode 35B. The insulating protective film 45 is formed of a material transparent to the light emitted from the organic EL element 12. Therefore, the insulating protective film 45 can transmit not only the light emission of the organic EL element 12 but the external light of the wavelength band common to the light emission of the organic EL element 12.

In the same plane as the anode 35A, a cathode auxiliary wiring 46 surrounding the anode 35A is formed around the anode 35A. The cathode auxiliary wiring 46 is provided to uniformize the in-plane potential distribution of the cathode 35B, and is electrically connected to the cathode 35B. In addition, the cathode auxiliary wiring 46 is arranged with a predetermined gap from the anode 35A, and an opening 46A is present between the anode 35A. Therefore, the cathode auxiliary wiring 46 maintains insulation with respect to the anode 35A.

Motion and effects

In the display unit 1 of the present embodiment, the pixel circuit 13 of each pixel 11R, 11G, 11B is turned on and off, and the organic EL element 12 of each pixel 11R, 11G, 11B is controlled. As the driving current is injected, holes and electrons recombine to emit light. This light multiplexes reflection between the anode 35A and the cathode 35B, passes through the cathode 35B, and is taken out to the outside. As a result, an image is displayed on the display unit 10.

By the way, in general, in the organic EL display unit, as shown in Figs. 6, 7, and 18, for example, light L of a part of the light generated in the organic layers 35C and 127C is reduced by the cathode 35B ( 127B) is not outputted and starts leaking to the adjacent pixel. For example, as shown in Fig. 19, when the light L started to enter the transistors T _Dr and T _WS (in particular, the channel 131) in the adjacent pixels, the light leakage current increases. This may cause malfunction of the pixel circuit 122.

In particular, when blue light having a short wavelength enters the channel 131, the TFT characteristics change, such as the minimum physical quantity voltage Vth, which causes the gate reaction to shift with time, and the long-term reliability of the TFT is deteriorated. Throw it away. When the channel 131 is composed of amorphous silicon (a-Si) or microcrystalline Si (μ-Si), the deterioration of the long-term reliability of the TFT becomes remarkable.

For example, as shown in FIG. 19, a pixel 120B included in one pixel 120 includes a pixel 120G included in the pixel 120 and another pixel 120 adjacent to the pixel 120. Is disposed between the pixels 120R included in. In this case, blue light L leaking from the organic layer 127C of the pixel 120B is incident on the transistor T _{Dr in the} pixel 120G and the transistor T _{WS in the} pixel 120R, and the transistor ( T _Dr , T _WS ) has a problem that the long-term reliability is reduced.

On the other hand, in the present embodiment, for example, as shown in FIG. 5, the transistors T _Dr and T _WS in the pixel 11R adjacent to the pixel 11B have a holding capacitor C _{s in the} pixel 11R. In comparison with the pixel 11B. In addition, the transistors T _Dr and T _WS in the pixel 11G adjacent to the pixel 11B are disposed away from the pixel 11B as compared with the holding capacitor C _{s in the} pixel 11G. Therefore, the distance A1 from the transistors T _Dr and T _{WS in the} pixel 11R to the organic EL element 12 in the pixel 11B is equal to the pixel 11B from the holding capacitor C _s in the pixel 11R. It is farther than the distance B1 to the organic EL element 12 in. Further, the distance A2 from the transistors T _Dr and T _{WS in the} pixel 11G to the organic EL element 12 in the pixel 11B is equal to the pixel 11B from the holding capacitor C _s in the pixel 11G. It is farther than the distance B2 to the organic EL element 12 inside. Thereby, compared with the case where distance A1 is closer than distance B1 and distance A2 is closer than distance B2, of the light L which leaked out from the organic layer 35C in pixel 11B, The incident amount of the transistors T _Dr and T _{WS in the} adjacent pixels 11B and 11G is small. As a result, even when the channels 51 and 55 are composed of amorphous silicon (a-Si) or microcrystalline Si (μ-Si), the degradation of the long-term reliability of the transistor can be reduced.

By the way, when the degradation of the transistors T _Dr and T _WS can be predicted, even if the characteristics of the transistors T _Dr and T _WS change, the voltage applied to the organic EL element 12 is set to a desired value (correction). It is possible to However, when the wavelength of the blue light is incident on the short channel of the transistor (T _Dr, T _WS), and the characteristics of the transistor (T _Dr, T _WS) changes with it, and it is difficult to correctly predict the change. For example, as shown in FIG. 8, the S value gradually decreases in the Vds-Ids characteristic of the transistors T _Dr and T _WS by irradiation with blue light, but it is very difficult to predict the change of this S value. Therefore, in consideration of deterioration due to blue light, it is not easy to set (correct) the voltage applied to the organic EL element 12 to a desired value.

However, in the present embodiment, as described above, the amount of incidence of light L leaking from the organic layer 35C in the pixel 11B into the transistors T _Dr and T _{WS in the} adjacent pixels 11R and 11G is small. . Therefore, since almost no correction in consideration of deterioration due to blue light is necessary, it is possible to maintain high display quality over a long period of time.

Variant

In the above embodiment, the case where the pixels 11R, 11G, 11B that emit three colors of light is provided in one pixel 11, but other emitting pixels may also be provided. In addition, pixels other than the pixels 11R and 11G may be provided in one pixel 11. Either way, in other pixels adjacent to the pixel 11B, the transistors T _Dr and T _WS are preferably arranged as far away from the pixel 11B as possible.

Module and Application example

Hereinafter, the application example of the display unit demonstrated by the said embodiment and its modification is demonstrated. The display unit according to the above-described embodiments includes an image signal or a video signal input from the outside, such as a television device, a digital camera, a portable personal computer such as a notebook personal computer, a mobile phone, or a video camera. It is possible to apply it to the display unit of the electronic equipment of all the fields displayed as an image.

module

The display unit of the above embodiment or the like is, for example, a module as shown in FIG. 9 and incorporated into various electronic devices such as Application Examples 1 to 5 described later. This module is provided with, for example, an area 210 exposed from a member (not shown) that seals the display unit 10 on one side of the substrate 2, and in this exposed area 210. The wirings of the timing control circuit 21, the horizontal drive circuit 22, the write scan circuit 23, and the power supply scan circuit 24 are extended to form external connection terminals (not shown). The external connection terminal may be provided with a flexible printed circuit board (FPC) 220 for inputting and outputting signals.

Application Example 1

10 shows the appearance of a television apparatus to which a display unit such as the above embodiment is applied. This television apparatus has the video display screen part 300 containing the front panel 310 and the filter glass 320, for example, and this video display screen part 300 is the same as the above-mentioned embodiment. It is comprised by the display unit.

Application Example 2

Fig. 11 shows the appearance of a digital camera to which a display unit such as the above embodiment is applied. This digital camera has, for example, a light emitting unit 410 for flash, a display unit 420, a menu switch 430, and a shutter button 440. It is comprised by display units, such as a form.

Application Example 3

12 shows the appearance of a notebook personal computer to which the display unit of the above-described embodiment or the like is applied. This notebook personal computer has a main body 510, the keyboard 520 for input operations, such as a character, and the display unit 530 which displays an image, for example, The display unit 530 is the said. It is comprised by display units, such as embodiment.

Application Example 4

Fig. 13 shows the appearance of a video camera to which a display unit such as the above embodiment is applied. This video camera includes, for example, a main body 610, a lens 620 for photographing a subject provided on the front side of the main body 610, a start / stop switch 630 and a display unit 640 at the time of shooting. This display unit 640 is comprised by display units, such as the said embodiment.

Application Example 5

Fig. 14 shows the appearance of a mobile phone to which the display unit of the above embodiment or the like is applied. The mobile phone is, for example, the upper box 710 and the lower box 720 connected by a connecting portion (hinges) 730, and the display 740, the sub display 750, and the picture light 760. And a camera 770. The display 740 or the sub display 750 is configured by display units such as the above embodiments.

As mentioned above, although this invention was demonstrated with each said embodiment, its modified example, and application example, this invention is not limited to them, A various deformation | transformation is possible.

For example, in the above embodiment and the like, the case where the display unit is an active matrix type has been described. However, the configuration of the pixel circuit 13 for driving the active matrix is not limited to that described in the above embodiment and the like. Therefore, it is possible to add a capacitor or a transistor to the pixel circuit 13 as necessary. In that case, in accordance with the change of the pixel circuit 13, the necessary driving circuit may be added in addition to the above-described horizontal driving circuit 22, the write scanning circuit 23, and the power supply scanning circuit 24.

In the above embodiment, the signal holding control circuit 21B controls the driving of the horizontal driving circuit 22, the write scanning circuit 23, and the power supply scanning circuit 24, but other circuits perform such driving. You may make it control. In addition, the control of the horizontal drive circuit 22, the write scan circuit 23, and the power source scan circuit 24 may be performed by hardware (circuit) or may be performed by software (program).

In the above embodiment and the like, the source and the drain of the transistor T _WS and the source and the drain of the transistor T _Dr are described as being fixed, but needless to say, depending on the direction in which the current flows, The opposing relationship between and drain may be inverse to the above description.

In the above embodiment and the like, the transistors T _WS and T _Dr are described as being formed by an n-channel MOS type TFT, but at least one of the transistors T _WS and T _Dr is a p-channel MOS. It may be formed by a TFT of a type | mold. When the transistor T _{Dr is} formed of a p-channel MOS type TFT, the anode 35A of the organic EL element 12 becomes a cathode in the above-described embodiment and the like, and the organic EL element 12 ) Cathode 35B becomes an anode. Note that in the above embodiments and the like, the transistors T _WS and T _{Dr do not} always need to be amorphous silicon TFTs or micro silicon silicon TFTs, for example, but may be low temperature polysilicon TFTs.

The present invention claims priority of Japanese Patent Application No. 2009-061713 filed with the Japan Patent Office on March 13, 2009.

One… Display unit
10... Display unit
11 ... pixel
11R, 11G, 11B... pixel
12, 12R, 12G, 12B... Organic EL device
13... Pixel circuit
20... Peripheral circuit
21 ... Timing control circuit
21A... Display signal generation circuit
21B... Display signal holding control circuit
22... Horizontal drive circuit
23 ... Recording scanning circuit
24 ... Power scan circuit
31A, 32A... gate
31B, 32B... sauce
31C, 32C... drain
33A, 33B... Terminals
34A, 34B, 34C, 34D... Contact
35A... Anode
35B... Cathode
35C... Organic layer
36A, 36B... Leader
40 ... Board
41... Gate insulating film
42, 45... Insulation shield
43 ... Insulation planarization film
44 ... Aperture regulation insulating film
44A... EL opening
C _S … Holding capacity
DSL… Drain wire
DTL… Signal line
L… Outer light
T _Dr , T _WS . transistor
WSL… Gate line

Claims (5)

A plurality of organic EL elements having different emission colors,
A display unit having a plurality of pixel circuits for each pixel, one for each organic EL element;
The pixel circuit includes a first transistor for recording that records a video signal, a second transistor for driving that drives the organic EL element based on a video signal recorded by the first transistor, and a sustain. With capacity,
The third transistor provided in correspondence with the second organic EL element adjacent to the first organic EL element among the first transistor and the second transistor is connected to the second organic EL element among the holding capacitors. A display unit, wherein the display unit is disposed far from the first organic EL element in comparison with the corresponding first storage capacitor. The method of claim 1,
The third transistor is disposed on the side opposite to the first organic EL element in relation to the first storage capacitor. The method of claim 1,
The first organic EL element includes an organic layer that generates light capable of deteriorating the first transistor and the second transistor. The method of claim 3, wherein
And the organic layer comprises a material emitting blue light. The method of claim 3, wherein
And said third transistor comprises a channel comprising amorphous silicon (a-Si) or microcrystalline Si (μ-Si).

Images